摘要:
An acoustic wave device comprising at least one surface acoustic wave filter and one bulk acoustic wave filter, the device including, on a substrate comprising a second piezoelectric material: a stack of layers including a first metal layer and a layer of a first monocrystalline piezoelectric material, wherein the stack of layers is partially etched so as to define a first area in which the first and second piezoelectric materials are present and a second area in which the first piezoelectric material is absent; a second metallization at the first area for defining the bulk acoustic wave filter integrating the first piezoelectric material, and a third metallization at the second area for defining the surface acoustic wave filter integrating the second piezoelectric material.
摘要:
Acoustic resonator comprising an electret, and method of producing said resonator, application to switchable coupled resonator filters.The resonator comprises: at least one piezoelectric layer (30); electrodes (24, 26) on either side of this layer; and at least one electret layer (32) between the electrodes, to apply a permanent electric field to the piezoelectric layer. The intensity of this electric field is determined to shift the resonance frequency of the resonator by a desired value. The piezoelectric layer may contain electrical charges to itself constitute the electret layer.
摘要:
An electromechanical device having a resonator using acoustic waves propagating laterally within a piezoelectric plane resonant structure and electrodes on a face of said structure. The resonant structure comprises: a transduction region having a transduction length and generating acoustic waves; a free propagation region for the acoustic waves, adjacent to the transduction region and defined the plane of the transduction region; the resonant structure length being equal to an integer number of half-wavelengths, the resonance frequency of said resonator equaling the average propagation velocity of the wave within the structure divided by said wavelength, to adjust the quality factor of the resonator fixed by the length of the resonant structure and the coupling coefficient fixed by the ratio of the transduction length over the length of the resonant structure; the resonant structure defined by the assembly of the transduction region and the propagation region being laterally bounded by reflection regions.
摘要:
An electrical signal combiner includes at least one first element and a second element respectively connected to a first input port and to a second input port, and a third element connected to an output port, the electrical signals being propagated between the input and output ports. The combiner includes a medium; and the first, second and third elements are acoustic wave transducers, the electrical signals being carried by acoustic waves propagated between the input and output ports within the medium. Advantageously, the first transducer and the third transducer are separated by an acoustic distance of (2k+1)λ/4 with k an integer greater than or equal to 0 with λ the acoustic propagation wavelength; the second transducer and the third transducer are separated by an acoustic distance of (2k′+1)λ/4 with k′ an integer greater than or equal to 0; and the first and second transducers are separated by an acoustic distance of (2k″+2)λ/4 with k″ an integer greater than or equal to 0—in such a manner as to, on the one hand, generate constructive interference at the output port and, on the other hand, to isolate the first and second input ports by destructive interference of acoustic waves at the ports.
摘要:
An acoustic wave bandpass filter comprises at least an input first acoustic wave resonator with an output surface, and an output second acoustic wave resonator with an input surface, said resonators being coupled to each other along a set direction, the input and output surfaces being substantially opposite, and at least one first phononic crystal structure between said input and output resonators and/or a second phonic crystal structure at the periphery of said resonators so as to guide the acoustic waves, generated by said input resonator, toward said output resonator along said set direction, the resonators ensuring an impedance conversion and/or a mode conversion.
摘要:
An acoustic structure comprising comprises a layer of material having a first Young's modulus called the intrinsic modulus and a first density called the intrinsic density, characterized in that the layer comprises at least one first zone having said first Young's modulus and said first density and at least one second zone buried in the volume of said layer of material and having a second Young's modulus and/or a second density obtained by implanting and/or by diffusing atoms into the volume of said layer.
摘要:
An acoustic wave bandpass filter comprises at least two bulk acoustic wave resonators, laterally coupled to each other acoustically, each resonator including a film of piezoelectric material and at least a first electrode and/or a second electrode, said bulk waves propagating in a direction perpendicular to the plane of the film of piezoelectric material, characterized in that: it further comprises at least a first phononic crystal structure between said resonators such that the transmission coefficient of the lateral acoustic waves can be decreased in a direction parallel to the plane of the piezoelectric film; and the first phononic crystal structure is formed in a matrix of dielectric material or with patterns made from dielectric material.
摘要:
An acoustic wave bandpass filter comprises at least two bulk acoustic wave resonators, laterally coupled to each other acoustically, each resonator including a film of piezoelectric material and at least a first electrode and/or a second electrode, said bulk waves propagating in a direction perpendicular to the plane of the film of piezoelectric material, characterized in that: it further comprises at least a first phononic crystal structure between said resonators such that the transmission coefficient of the lateral acoustic waves can be decreased in a direction parallel to the plane of the piezoelectric film; and the first phononic crystal structure is formed in a matrix of dielectric material or with patterns made from dielectric material.
摘要:
A guided acoustic wave resonant device is provided. The device comprises at least two filters (F1, . . . , Fi, . . . , FN), each filter comprising at least two acoustic wave resonators (R11-R12, . . . , Ri1-Ri2, . . . , RN1-RN2), each filter having a useful frequency band (BF1, . . . , BFi, . . . , BFN) centered on a central frequency (f1, . . . , fi, . . . , fN), each resonator comprising at least one suite of inter-digitated upper electrodes exhibiting a periodic structure of period (Λij) and a layer of piezoelectric material, each resonator having a coupling coefficient (k21, k22, . . . , k2n) and a resonant frequency (fr1, . . . , fr2, . . . , fN), wherein at least one of the resonators comprises a differentiation layer (CDfi) making it possible in combination with the period of the inter-digitated electrodes to modify the coupling coefficient of the said resonator, the useful band and the central frequency being determined by the resonant frequencies and the coupling coefficients of the resonators which are adapted so as to have a determined useful bandwidth.
摘要:
An acoustic wave device comprising at least one surface acoustic wave filter and one bulk acoustic wave filter, the device including, on a substrate comprising a second piezoelectric material: a stack of layers including a first metal layer and a layer of a first monocrystalline piezoelectric material, wherein the stack of layers is partially etched so as to define a first area in which the first and second piezoelectric materials are present and a second area in which the first piezoelectric material is absent; a second metallization at the first area for defining the bulk acoustic wave filter integrating the first piezoelectric material, and a third metallization at the second area for defining the surface acoustic wave filter integrating the second piezoelectric material.